Here is one report, I remember this now.
Study concludes parasitic worms cause frog deformitiesTuesday, May 07, 2002By
Jeff Barnard, Associated PressGRANTS PASS, Ore. — After slogging through 101
ponds and wetlands in five western states, scientists on the trail of a
mysterious outbreak of deformities in frogs have settled on a microscopic
parasitic flatworm as the prime suspect.
Linked with existing laboratory studies showing that the trematode known as
Ribeiroia ondatrae can cause the frogs to sprout extra legs, the new field work
closes the loop by showing a direct correlation between the prevalence of the
parasite and the number of deformed frogs, scientists said.

The rest of the article can be found here
http://www.enn.com/news/wire-stories...2/ap_47144.asp

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